You will have to change the companion flanges from your current diffs, to the 4:11's that you are intending on installing. You say that these 4:11 gear sets are out of a "late model". In therory, you should not have a problem swapping the flanges, but, I have seen proclaimed " late modle" diffs/gear sets that did not have the "fine spline" pinions in them.
In the event that you end up having the "coarse spline"(which, until you remove the flange, you can not tell) 4:11 diffs, you can get a companion flange that will work for your bolt pattern on your '86, from Downey, or perhaps Randys ring and pinion.

Count the teeth and do the math before going through all the work of setting these up, and chaging them over. I know people who have not, and spent a lot of time and effort to install 3:73's back into thier trucks!

re-drill em thats what i'm gona do, most of the flanges i've seen that are multi bolt are fine splines :-\ now if you can get some fj62 drop outs BLING BLING 4.10 and fine spline correct flanges kind hoppen to swap my 4 drop outs for a pair of those

You won't be able to re-drill the companion flange on the 40 diffs--it's square-ish and the holes are right at the four corners. I just put a '76 FJ40 diff into the rear of my 60. Can you say pain in the ass? I had to buy an after-market companion flange that was round with coarse splines. It was drilled for the early bolt pattern. Took it to a machine shop and they rotated it 1/8 turn (so the new holes were pretty much in between the old holes) and redrilled. Works fine except I never did get damn load on the pinion adjusted correctly yet. Vibrates like a mo-fo. But I don't care, my full-float rear end will be here at the end of the week and I'll be droppin' my 80 series e-locker diff in there. FWIW, I'll have that flange for sale when it's all done and under (which will be atleast two weeks).

[quote author=kling-on link=board=1;threadid=7989;start=msg67751#msg67751 date=1069764425]
re-drill em thats what i'm gona do, most of the flanges i've seen that are multi bolt are fine splines :-\ now if you can get some fj62 drop outs BLING BLING 4.10 and fine spline correct flanges kind hoppen to swap my 4 drop outs for a pair of those
[/quote]

[quote author=Poser link=board=1;threadid=7989;start=msg67508#msg67508 date=1069720856]
Count the teeth and do the math before going through all the work of setting these up, and chaging them over. I know people who have not, and spent a lot of time and effort to install 3:73's back into thier truck.[/quote]

That's a damn good idea. But FYI, the FJ40 4.11s have 37 ring gear teeth and 9 pinion gear teeth and the FJ60 3.70s have 37 ring gear teeth and 10 pinion gear teeth. So you gotta count both of them. And count 'em twice or three times and let somebody else try counting once or twice to be sure--and make sure you haven't had too many or you could waste a lot of time--right Mixmaster!? :

All you need, and I know because my 4.11's in my 82 fj 60 are from a 71 Fj40, are the driveshaft ends. that's it. pop your driveshafts off, pull the ends off, put the 40 ends (that match the diffs) on, and turn the shafts around. Presto, chango, set to go. No drilling, dissassembly, etc, nada. you can take the hard way, but why?

Sorry to those who offered good suggestions, but this is waaay easier.

[quote author=bernefj60 link=board=1;threadid=7989;start=msg67976#msg67976 date=1069794812]
all these are good suggestions but TOTAL wastes of time.

All you need, and I know because my 4.11's in my 82 fj 60 are from a 71 Fj40, are the driveshaft ends. that's it. pop your driveshafts off, pull the ends off, put the 40 ends (that match the diffs) on, and turn the shafts around. Presto, chango, set to go. No drilling, dissassembly, etc, nada. you can take the hard way, but why?

Sorry to those who offered good suggestions, but this is waaay easier.